2-Hydrazinylpyrimidine → 2-[5-(4-Fluorophenyl)-3-(1-methylethyl)-1H-pyrazol-1-yl]pyrimidine

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-(4-fluorophenyl)-4-methyl-1,3-pentanedione (preparation disclosed in Example 1, Step A) (155 g, 0.74 mol) in 1 l glacial acetic acid was added, under a N2 atmosphere at room temperature, 90 g (0.82 mol) of 2-hydrazinopyrimidine (prepared according to J. Chesterfield et al., J. Chem. Soc., 3478, 1955). This was heated to 60° C. for one hour, cooled to room temperature and poured into 4 l saturated NaHCO3 aqueous solution. The resulting mixture was extracted with EtOAc and the organic layer was separated and washed with water and brine. This solution was dried over MgSO4, filtered and concentrated in vacuo. The crude reaction mixture was flash chromatographed on a silica gel column, eluting with 10% EtOAc-toluene yielding 16.4 g of 2-[5-(4-fluorophenyl)-3-(1-methylethyl)-1H-pyrazol-1-yl]pyrimidine and 94 g of 5(3)-4-fluorophenyl)-3(5)-(1-methylethyl)-1H-pyrazole, mp 102°-103° C.

Provenance & Evidence